1. Field of the Invention
The present invention relates generally to a water heating control system, and more specifically, to a microprocessor-based system for controlling the temperature and increasing the energy efficiency of lavatory sinks, showers, baths, etc.
2. Description of the Related Art
Conventional tankless water heaters can heat water precisely to desired temperatures, but this temperature is typically set locally, at the tankless water heater, and typically at 140 degrees F. The user must then mix cold water with the heated water to obtain the desired user temperature. This is a waste of energy and is inefficient. To counteract this, the inventions disclosed in U.S. Pat. No. 4,713,525 issued in April 1996 to Russell et al. and U.S. Pat. No. 5,504,306 issued in December 1987 to Eastep use a microprocessor based remote control pad to heat water to the desired user temperature without mixing. The problem with these devices is that they do not have preset buttons to serve as a memory for storing optimal temperatures, nor do they have diagnostic or troubleshooting capabilities. Moreover, Eastep and Ressell et al. do not provide a device combining the efficiency and precision of electronic temperature control with the charming familiarity of hot and cold conventional water knobs.
Other patent which have some relevance to the present invention include: U.S. Pat. No. 5,479,558 issued in December 1995 to White, Jr., et al., describing a flow-through tankless water heater with a flow switch and a heater control system; U.S. Pat. No. 5,020,127 issued in May 1991 to Eddas et al., describing a tankless electric water heater; and U.S. Pat. No. 4,970,373 issued in November 1990 to Lutz et al., describing an electronic temperature control system for a tankless water heater.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
This invention is a remote control tankless water heater system. The purpose of this invention is to obviate the need to mix hot and cold water in a sink, faucet, or shower, which is inefficient and wasteful. In one embodiment, there is a key pad control system, including preset buttons which serve as a memory for storing optimal user temperatures for up to six people, automatic troubleshooting diagnostics, and scald protection. In another embodiment, conventional knobs, instead of a key pad, are used to control the water temperature and flow rate.
Once a key pad selection is made, the microprocessor does a diagnostic check of the whole system. A thermistor, located near a water heater outlet, monitors the outlet temperature of the water en route to the faucet. The change in resistance of the thermistor is measured and translated into a temperature. The microprocessor then compares this temperature to the temperature selected by the user. The second embodiment of the tankless water heater system also includes a water heater assembly, and a user interface. However, instead of having a key pad control panel, conventional mixing knobs such as those used with showers, kitchen sinks, lavatory sinks, etc., are employed. In addition to controlling the water temperature, the knobs also control the flow of water in the system but not in the conventional manner. The user thinks that he or she is mixing hot and cold water when turning knobs to obtain the desired temperature and flow rate. In actuality, the temperature and flow rate are guided by a microprocessor, and they are based upon the ratio of rotation between the two knobs and the aggregate rotation of the knobs, respectively.
Accordingly, it is a principal object of the invention to improve the energy efficiency and the reliability of residential and commercial water outlets.
It is another object of the invention to provide an electronic mechanism that enhances water conservation.
It is a further object of the invention to modernize water faucets, while retaining their charm and antiquity.
It is yet another object of the invention to prevent freezing and/or scalding temperatures, and to thus prevent epidermal injuries.